Brennan Heating & Cooling Inc provides residential and commercial heating, cooling and air-care systems in Great Falls. Established in 1990, it carries on a sheet-metal tradition begun with B&B Heating in 1977.
Last Updated October 3, 2026.
Great Falls and surrounding communities.
Brennan Heating & Cooling Inc is one of 6 HVAC companies ProsGrade lists in Great Falls, Montana.
8 services listed, including Heating and cooling systems, Mini-split ductless systems and Controls, air cleaners and humidification. Open weekdays, closed on weekends. Rated 4.5 from 18 reviews.
How Brennan Heating & Cooling Inc compares with the other 5 HVAC companies on ProsGrade in Great Falls, using public Google ratings and review counts.
Several customers praise the service and workmanship on heating and cooling jobs. Specific accounts describe an after-hours AC call that led to a working system the next morning with needed parts, and a furnace-and-air-conditioner installation that included duct repairs after flood damage. One customer, however, reports that a home AC unit installed by Brennan held its charge for only a year and says the company did not stand behind the work; the customer also says annual leaks at the fittings were described as normal.
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Brennan lists a one-year labor-and-parts warranty; equipment is subject to the manufacturer's warranty.
The company charges for coming out to inspect equipment and can estimate repairs after the visit.
For after-hours calls or unanswered calls, Brennan says it will get back to callers who leave a brief message.
Its guidance lists an expired warranty with major or costly parts needed, an age over 15 years, or frequent repairs as replacement considerations.
